add auxGet function for returning arbitrary auxiliary fields
fix for c2hs in Mac OS X 10.9 Mavericks (see https://github.com/haskell/c2hs/issues/57 and https://github.com/tmcdonell/cuda/pull/4/files)
add auxGet variants for each return type, plus a general auxGet with overloaded return types
Merge pull request #2 from benwbooth/master

add auxGet function, c2hs fix for Mac OSX 10.9